100. MARSILEACE^;. 429 



involucres forwards. Valves of the involucre convex or gibbous 

 throughout, touching only by their edges which are quite entire. 

 Amongst moss in damp and shady places. P. VII. 



Suborder III. Osmundacece. Tribe VI. Osmundea. 



18. OSMTJNDA Linn. Flowering-fern. 



1. 0. regalis (L.); fronds bipinnate, pinnules oblong nearly 

 entire dilated and slightly auricled at the base, clusters panicled 

 terminal. E. B. 209. IV. 331. Fronds erect or drooping, 18 

 feet high. Boggy places. P. VII. IX. 



Subord. IV. Ophioglossacece. Tr. VII. Ophioglossea. 



19. BOTRYCHIUM Sw. Moon-wort. 



1. B. Lunaria (Sw.) ; frond pinnate solitary, pinnae lunate or 

 fanshaped notched or crenate. E. B. 318. N. 137. Height 

 3 6 in. Pinnae with veins radiating from the petiole, some- 

 times deeply notched. Fronds usually solitary, but sometimes 

 two on the same stalk. Pastures. P. VI. VII. 



[.B. rutaceum (Sw.) ; frond triangular-rhomboidal pinnatifid 

 solitary, pinnae 7 9 linear incise-serrate decreasing upwards. 

 N. ed. 3. 322. Veins not radiating. The species is doubtful. 

 Sands of Barry, Forfar. P. VIIL] 



20. OPHIOGLOSSUM Linn. Adder's-tongue. 



1. 0. vulgatum (L.) ; frond ovate obtuse. E. B. 108. N. 349. 

 Height 4 12 in., erect. Spike clubshaped, usually rather 

 longer than the frond, sometimes very long. Pastures. P. V. VI. 



[2.? 0. lusitanicum (L.); frond linear-lanceolate. N. ed. 3. 

 331. S. 47. Height 12 inches, erect. Petit Bo Bay, Guern- 

 sey. Mr. G. Wolsey. P. L] 



Order C. MARSILEACE^l. 



Creeping plants with alternate erect leaves having a circinate 

 vernation. Fructification consisting of globular nearly sessile 

 coriaceous bodies with 3 or 4 cells and containing sacs including 

 either other bodies that germinate or loose granules. 



